This invention relates to a magnetic recording medium, specifically a magnetic recording medium in the surface of which visible patterns (information) can be written, its production method and its use.
This invention can be effectively applied to magnetic cards including prepaid cards such as a telephone card wherein figures and the like corresponding to the contents of magnetic recording are printed to enable the magnetically recorded contents of said recording medium to be macroscopically seen.
Magnetic cards are handy to carry and are widely used as useful cards. They have a magnetic recording layer formed on a desired area of the surface of a card base with proper thickness.
Magnetically recorded information such as the frequency of use and the remainder can not be macroscopically seen in a magnetic card and therefore the remainder was indicated by punched holes and the like in a prepaid magnetic card. However, since the precise remainder is not indicated, cash or another magnetic card must be used when the remainder is insufficient. It is sometimes required to print the frequency of use, the remainder and the like on the card surface in order to avoid such a situation.
Conventionally, printing is generally performed on the surface of a magnetic card opposite to its magnetic recording layer by a wire dot print head through a pressure sensitive ink ribbon, by a thermal print head through a heat sensitive ink ribbon or by applying a thermal print head to a heat sensitive recording layer formed on the card surface. However, a desired design is generally printed on the surface of the magnetic card opposite to its magnetic recording layer and a wide area for the above printing is not desirable in terms of the above design.
Conventionally, printing is performed on the side of the magnetic recording layer of the magnetic card in some cases and in such cases the magnetic recording layer is partially formed on the card base and printing is performed on an area different from said recording layer. Therefore, it is impossible to make both the magnetic recording area and the printing area sufficiently large.
When a heat sensitive recording layer is formed on the card surface, since the recording layer is deteriorated (changes with the passing of time) by the accumulation of external heat energy, the contents of recording (visible patterns) are hard to see and recording is difficult.
Recently, magnetic cards wherein a larger amount of information is recorded have come to be used and therefore it is desirable that the magnetic recording area be large and the printing area be as large as possible. Furthermore, since it is desirable that printed letters be as large as possible to enable easy reading, it is preferable that the printing area be as large as possible from this point of view as well.